You have a conditional (2-year) green card that is about to expire. You have filed Form I-751 to remove the conditions. However, the time between filing and receiving the 10-year green card can be over 18 months!!!
What if you need to travel abroad during that time?
After a conditional green card has expired and before your new 10-year green card arrives, it's necessary for a conditional resident to carry the following items when traveling abroad:
• Valid, unexpired passport
• Expired conditional green card
• Valid, unexpired I-797C, Notice of Action
USCIS will mail you the I-797c Notice of Action after you file Form I-751. It's a receipt letter that will also provide an extension (typically for 18 months) to your conditional residence. However, it may take USCIS several weeks to send the letter after you have submitted your application. You should contact USCIS to get the most up to date information.